Scaffold



Pnt-nadoen 31, 1944 SCAFFOLD Thomas M. num and Anthony charles Marton, McKeesport, Pa., assixnors to National Tube Company, a corporation of New Jersey Application July 15, 1943, Serial No. 494,862

6 Claims.

This invention relates to scaflolds and, particularly, to an improved truss unit for scaffolds of the portable type.

In our Patent No. 2,181,784, dated November 28, 1939, there is disclosed a portable scail'old which consists generally of a plurality of interchangeable tubular leg sections and, horizontal and diagonal reenforcing members which telescopically engage with each other to form a completed scaffold of any desired design or height. 'oftentimes it is desirable to provide a passageway in under scaifolds so as to avoid, as much as possible, obstructing sidewalks, door areas, or other passageways, in order to permit business as usual when and wherever the scailold is being used. While the general construction and arrangement of this scaffold disclosed in our patent is entirely satisfactory, there is no provision therein for permitting such passage under the scaffold through the lowermost leg sections thereof unless some of the horizontal and diagonal reenforcing members are deleted therefrom. However, if such members were not used in order to provide such a passageway, it would considerably weaken the scail'old and be unsteady. According to the present invention there is provided a truss unit which can be incorporated with the scaffold disclosed in our patent so as to provide a passageway in under the scaiold and which is deemed to be an improvement over our former scaifold.

Accordingly, it is the general object of the present invention to provide an improved scaffold having the lowermost section constructed and arranged so as tc'permit passage in under the scaffold without sacrificing strength or steadiness thereof. l

Itis another object of the invention to provide an improved truss unit made from tubular stock to obtain the maximum Strength and lightness, which may be easily and conveniently incorporated with existing scaffolds without the need of any additional connecting parts or members.`

It is a, further object of this invention to provide an improved truss unit which may be conveniently assembled at any desired point in the scaffold, and, at the same time, a truss unit which is simple and inexpensive in its construction, and eiiicient and effective in its use.

Various other objects and advantages of this invention will be more apparent in the course of the following specification and will be particularly pointed out in the appended claims.

In the accompanying drawingsthere is shown, for the purpose of illustration, one embodiment and a modiiication thereof which our invention may assume in practice.

In these drawings:

Figure 1 is a front elevational view of the scaffold of our invention showing our improved truss unit incorporated therewith;

Figure 2 is a side elevational view thereof;

Figure 3 is a top view of the same;

Figure 4 is a sectional view taken on line IV-IV of 'Figure 1;

Figure 5 is a vertical sectional view'through one of the joints of one of the legs showing the arrangement of the leg sections and the other reenforcing members; y

Figure 6 is a front elevational view of a modiiied construction of our improved truss unit; and

Figure 7 is a side elevational View thereof.

There is shown in the drawings, for the purpose of illustration, our improved scaffold arranged in a square design with the vimproved truss unit of the present invention incorporated therewith. It will be understood that our scaffold can be assembled into different shapes if desired or made tolbe continuous so as to provide an .elongated ,arranged on one end thereof which is substantially equal in diameter to the inner diameter of the tubular section 2. The extension 3 of each Vof the leg sections 2 consists preferably of a hollow cylindrical piece of metal extending into the end of the tubular leg section and securely welded thereto. There is provided a plurality of ledger l or horizontal tubular reenforcing members 4 with each having a vertical extending sleeve 5 arranged on 'each end thereof which is integrally connected thereto preferably by means of welding. The horizontal members are adapted to extend between the tubular leg sections 2 and the sleeves carried thereby are adapted to telescopically engage the extensions 3 carried thereby. 'There is also provided a plurality of braces or reenforcing tubular members 6 which Each of the braces 6 is diagonal in tension 3 of a ieg-section 2. There is also arranged, in a horizontal plane between each of the diagonally opposed leg sections, as shown in Figures 4 and 5, a reenforcing tubular crossbar or member 3. Each of these cross-bars 8 also has flattened apertured ends 9 which are adapted also to telescopically engage with extensions 3 of the legsections .2. I

There is arranged at the bottom of each of the legs a relatively short tubular leg section I having an integral extension Iiis arranged on the upper end lthereof similar to the extension 8 on the longer leg sections 2. n the bottom end of cachot the short leg sections It there is'mounted a flange or pedestal II which rests upon the ground or surface upon which the scaffold is to be erected.

There is arranged on top of the topmost unit oi? the scaifold, preferably a working platform.

This platform consists preferably of four railing posts i2, four horizontal ledger or reenforcing braces I3 and, preferably, a wood floor I4. If desired, a toe board I may be provided.

It will be understood that the connecting portions on the ends of each of the members as above described telescopically engage with the extensions 3 of the leg sections 2 at each of the Joints or panel points. as they are sometimes called. In other words, the sleeve portions 5 of the horizontal members and the flattened apertured ends land 9 of the diagonal braces B and reenforcing members 8 respectively, tele-- scopically engage with the extensions 3 at each joint between the leg sections 2 in superimposed relation to each other so that all the forces or stresses which are transmitted to these members will be transferred directly to the extensions 3 at each of the panel points or joints, thereby eliminating the forces or 'stresses from being transmitted directly to the leg sections. Thus it will be seen by providing such a construction that all of. the forces or stresses transmitted to the members are transferred to the exleg sections Ill. The improved truss unit of our invention is then. positioned in the lowermost section by telescoping the attened apertured tensions 3 at substantially one point or at least confined within a minimum distance therealong, that is, all of the vertical, horizontal and diagonal stresses meet substantially at one point at each of the joints or panel points, thereby reducing the bending or turning moment in the vicinity of the Joints and on the leg sections to a minimum.

It will be understood that every Joint in the assembled scaifold, except they joints at the base,

must be composed of the members as hereinbefore described, but if for any reason it is desiredI Ato omit any oi' these members from the structure, it will be necessary to provide a filler or washerat the joint of substantially the same thickness as the member omitted so as to make the joint tight.

According to the present invention, the preferred form of the improved Vtruss unit, as shown i in Figures 1 and 2 of the drawings, comprises a horizontally disposed tubular member I6 with each end thereof preferably flattened as at I6* ends I9 thereof with the extensions I Ila of the tubular members Iii across the desired span between the legs, Where it is desired to provide a passageway. The braces 5, which are diagonal Y inra vertical plane, are then positioned along the sides to form the lowermost section or unit with one of the flattened apertured ends 'l thereof telescopically engaging the extensions l of the tubular members I0. The lowermost tubular leg sections 2 are then positioned on the extensions l0 of the short tubular members I0 so as to form the lowermost section of the scaffold, and the extensions 3 are telescopically engaged with both the flattened apertured ends I6* on the horizontal member I6 of the truss unit and the opposite ends 'i of the vertical diagonal braces t. The horizontal diagonal members 3 are then positioned so that their attened ends telescopically engage with the extensions 3 of the lowermost leg sections 2. Additional horizontal members s are then positioned on the extensions 3 of the lowermost leg sections 2 of the scaffold and the completion of the assembly of the same is performed as hereinbei'ore described, so as to provide a scaffold as shown in Figures 1 and 2 of the drawings. It will be understood that the improved truss unit oi' our invention may bel stantially the same as the preferred construction but differs therefrom in that there is provided relatively short tubular' leg sections 20 constructed in the same manner as the leg sections 2. In this construction, the attened apertured ends 2| of the downwardly extending free ends or knee braces 22 of the inverted U-shaped member 2l, telescopically'engage with the extensions 3 on the upper ends of the lowermost leg sections or the leg sections positioned therebelow instead of -the extensions l0 of the relatively short leg sections lli arranged at the bottom of the legs, as in the case of the` preferred construction, and the flattened apertured ends 24 of the horizontal member 23 telescopically engage with the extensions 3 of the short tubular leg sections 20.

As a result of our invention, it will be seen that there is provided a truss unit which can be easily and quickly assembled at any point in the scaffold without weakening the construction thereof in any manner so as to provide a passageway in under or through the scaifold at any section therein as desired. It will be understood that if it is desired to provide a passageway entirely through the scaold, that the truss unit of the present invention is assembled in those sections through which it is desired that a passageway be provided. Generally such passageways are arranged only in the lowermost sections, and in such event, it will be understood that the truss unit is positioned in the oppositely disposed sides' of the lowermost sections, and if the scaffold is continuous and consists of more than four legs, the truss unit will be positioned in each succeeding lower section of the scaffold throughout the length thereof.

While we have shown and described a preferred embodiment of `our invention and a modification thereof, it will be understood that these embodiments are merely for the purpose of illustration and description and that various other forms may be devised within the scope of our invention, as defined in the appended claims.

We claim:

1. A scaffold comprising a plurality of tubular leg sections which are alike and interchangeable with each other, an extension arranged on one end of each of said leg sections and extending outwardly from the end thereof, each of said extensions being integrally attached to the end of its respective leg section and adapted to telescopically engage with the opposite end of an adjacent leg section, a plurality of horizontally and diagonally arranged tubular reenforcing members extending between said leg sections with each having a connecting portion arranged on each end thereof which is adapted to telescopically engage with said extensions, and a pair of spaced apart angularly downwardly diverging straight members connected at their tops by a straight portion securely `attached at least to some of said horizontal reenforcing members so as to provide substantially an inverted U-shaped passageway centrally between the leg sections with which it is used, each of said downwardly extending members having an aperture arranged in the lower end thereof which is adapted to telescopically engage with the extension arranged between the joints of the respective leg sections with which it is used and those positioned immediately therebelow.

2. A scaffold comprising a plurality of tubular leg sections which are alike and interchangeable with each other, an extension arrangedon one end of each of said leg sections and extending outwardly from the end thereof, each of said extensions being integrally attached to the end of its respective-leg section and adapted to telescopically engage with the opposite end of an adjacent leg section, a plurality of horizontally and diagonally arranged tubular reenforcing members extending between said leg sections with each having a connecting portion arranged on each end thereof which is adapted to telescopically engage with said extensions, and a substantially inverted U-shaped member securely attached to at least one of said horizontal menibers with the free ends thereof extending angularly downwardly therefrom so as to provide substantially an inverted U-shaped passageway centrally between the leg sections with which it is used, each of the free ends'of said inverted U-shaped member having a lateral extension for-med with an aperture arranged to telescopically engage with the extension arranged between the joints of the respective leg sections with which it is used and those positioned immediately therebelow.

3. A scaold comprising a plurality of legs, each oi' said legs including a plurality of tubular leg sections which are alike and interchangeable with each other, an extension arranged on one end of each of said leg sections and extending outwardly from the end thereof, each of said extensions being integrally attached to the end of its respective leg section and adapted to telescopically engage with the opposite end of an adjacent leg section, a plurality of horizontally and diagonally arranged tubular reenforcing members extending between said leg sections with each having a connecting portion arrangedV on each end thereof which is adapted to telescopically engage with said extensions, a relatively short tubular member arranged at the bottom of each of said legs, each of said last mentioned tubular'members having a similar extension integrally arranged therewith on the upper end thereof having an outer diameter substantially equal to the internal diameter of said leg sections and which is adapted to telescopically engage with the open end of any one of the same, a truss unit arranged at the extreme bottom of said scaffold between any two of the lowermost sections of any leg, said truss unit comprising a horizontal member having an aperture arranged in each end thereof which telescopically engages with the extension arranged between the joints of the two respective lowermost leg sections and the two leg sections positioned immediately thereabove, and a pair of spaced apart angularly downwardly extending tubular members securely atvend oi' each of said leg sections and extending outwardly from the end thereof, each of said extensions being integrally attached to the end of its respective leg section and adapted to telescopically engage with the opposite end of an adjacent leg section, a plurality of horizontally and diagonally arranged tubular reenforcing members extending between said leg sections with eacn having a connecting portion arranged on each end thereof which is` adapted to telescopically engage with said extensions, a relatively short tubular member arranged at the bottom of each of said legs, each of said last mentioned tubular members having a similar extension integrallyk arranged therewith on the upper end thereof having an outer diameter substantially equal to the internal diameter of said leg sections and which is adapted to telescopically engage with the open end of anyone of the same, a truss unit arranged at the extreme bottom of said scaffold between any two of the lowermost sections of any ieg, said truss unit comprising a horizontal member having an aperture arranged in each end thereof which telescopically engages with the extension arranged between the joints of the two respective lowermost sections and the two leg sections positioned immediately thereabove, and a substantially inverted U-shaped member securely attached to said last mentioned horizontal member with the free ends thereof extending angularly downwardly therefrom sok as t'o provide substantially an inverted U-shaped passageway centrally between the lowermost leg sections, each oi the free ends of said inverted U-shaped member having an aperture arranged in the extreme lower end thereof which'is adapted to telescopically engage with the extension of the respective relatively short tubular members positioned below the lowermost leg sections.

5. A truss unit for a portable scaffold of the class described comprising a tubular member which is adapted to be horizontally disposed in the scaffold, a pair of spaced apart angularly downwardly diverging members securely attached to said tubular member so as to provide substantially an inverted U-shaped opening therethrough centrally thereof, and apertured portions on each end of said tubular member and the extreme lower end of each of said downwardly extending members for detachably coupling the same to the scaffold at the joints thereof.

` 6. A truss unit for a portable scaffold of the c lass described comprising a tubular member which isr adapted to be horizontally disposed in the scaffold, a substantially inverted U-shaped member securely welded to said horizontal member centrally thereof with the free ends thereof diverging angularly downwardly therefrom so as to provide substantially an inverted U-shaped opening therethrough centrally of the truss, and apertured portions on each end of said tubular member and the extreme lower end of each of the free ends of said inverted U-shaped member for detachably coupling the same to the scaffold at the joints thereof.

THOMAS M. DUGAN. ANTHONY CHARLES-MARTON. 

